Charles c



(No Model.)

, G. 0. TRAPP.

REVOLVING CHAIR.

No. 424,083. Patented Mar. '25. 1890.

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UNITED STATES PATENT OFFICE.

CHARLES C. TRAPP, OF PORT IVASHINGTON, WISCONSIN.

REVOLVING CHAIR.

SPECIFICATION forming part of Letters Patent No. 424,083, dated March 25, 1890.

Application filed August 3, 1889. Serial No. 319,623- (No model.)

To all whom it may concern:

Be it known that I, CHARLES O. TRAPP, of Port WVashiugton, in the county of Ozaukee and State of WVisconsimha-ve invented newand useful Improvements in Revolving Chairs; and I do hereby declare the following to be a full, clear, and exact description of said invention, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

It is common to support the revolving seat of a chair by a spindle with a screw-thread turning in a head fixed on the legs of a chair, by which device the seat of the chair may be rotated while the legs remain stationary, at the same time raising and lowering the seat with reference to the legs by reason of the screw-thread on the spindle.

My invention is of a device whereby the seat of a chair is permitted to revolve without raising or lowering it with reference to the legs, the adjustment up and down being secured by independent mechanism.

In the drawings, Figure 1 is an elevation of my improved device. Fig. 2 is a central vertical section of the same device. Fig. 3 is a transverse section on line 3 3 of Fig. 2.

A is a metal head, provided with sockets B B, adapted to receive therein the upper extremities of the legs 0, on which it is permanently supported rigidly. The metal head A is provided with a central vertical aperture, in which the cylindrical spindle D is fitted and moves .freely. A bracket E, adapted to support the ch air-seat thereon, is fixed rigidly on the top of the spindle D, being conveniently secured thereto by means of the screw F, though any other equivalent means of securing the bracket to the spindle could be used. An arm G has an aperture at one end, through which shank N of the spindle D passes and in which it rotates freely, and at the other end the arm G carries rigidly affixed thereto at right angles a screw H, which project-s through sockets thereforin the side of the head A, and is provided with a milled nut I, turning thereon in arecess therefor in the side of the head A, which nut bears at its upper and lower ends against the walls of said recess. A set of friction-wheels K K K are preferably used, having their journals in bearings therefor in downwardly-projecting flanges L L, rigid on the bracket E, which travel on the arm G and support the bracket and its load thereupon.

The spindle D is preferably provided with a shoulder M, the part above the shoulder forming a shank N of somewhat smaller diameter than the main part of the spindle, which shank only enters the aperture in the arm G, whereby the spindle has but slight endwise movement in the arm G, and may not be withdrawn therefrom without releas ing the bracket E from the spindle. One or more pins 0 insertedin the spindle D would support the arm G successfully, and the shoulder M could be omitted.

It will be understood that the seat which is supported on the bracket E may be rotated horizontally with the spindle D, and that the seat will not be raised or lowered by such rotation, but that the seat supported on the bracket E is supported and travels around (on the friction-wheels K K) on the arm G, and that the seat is elevated or lowered by turning the nut I on the screw H, whereby the screw I1 is raised or lowered vertically in the head A, thereby carrying the bracket E, with its superimposed structure, up or down, as desired. 7

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination, with the metal head supported on the legs of a chair and aspindle rotating therein, which spindle is adapted to be secured to the seat of a chair, of a screw provided with an arm, through which the spindle is passed loosely, which screw passes through sockets therefor in the metal head, and a nut turning on the screw and bearing at its ends against the metal head, substanvided with friction-wheels K K and a spindle D, of a head A, a therein-guided screw H, provided with a rigid arm G, and a nut I, turning 15 on the screw II and bearing against the head A, substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

CHARLES C. TRAPP. Witnesses:

JOHN NEUEM, GUSTAV GGTZE. 

